Description:
Changes introduced to the HTTP BIO connector to support Servlet 3.0
asynchronous requests did not fully account for HTTP pipelining. As a
result, when using HTTP pipelining a range of unexpected behaviours
occurred including the mixing up of responses between requests. While
the mix-up in responses was only observed between requests from the same
user, a mix-up of responses for requests from different users may also
be possible.

Mitigation:
Users of affected versions should apply one of the following mitigations:
- Upgrade to a Tomcat 7.0.12 or later
- Switch to the NIO or APR/native HTTP connectors that do not exhibit
this issue

Credit:
This issue was identified by Brad Piles and reported via the public ASF
Bugzilla issue tracking system.
The Apache Tomcat security team requests that security vulnerability
reports are made privately to security (at) tomcat.apache (dot) org [email concealed] in the first
instance.